How to flush DNS cache in Linux? Similar to what you can do in Windows with this command: ipconfig /flushdns Thanks!

I want to disable certain hosts on a local Ubuntu Linux box by setting their host names to non-routable IPs. However, it looks like on that box DNS has higher priority over my HOSTS file so the changes that I make to the hosts file are being ignored. How can I make HOSTS file to take priority over DNS lookups?